package com.shujia.flink.tf

import org.apache.flink.api.common.functions.FlatMapFunction
import org.apache.flink.streaming.api.scala._
import org.apache.flink.util.Collector

object Demo3FlatMap {
  def main(args: Array[String]): Unit = {
    val env: StreamExecutionEnvironment = StreamExecutionEnvironment.getExecutionEnvironment

    val linesDS: DataStream[String] = env.readTextFile("data/words")

    val flatMapDS: DataStream[String] = linesDS.flatMap(new FlatMapFunction[String, String] {
      override def flatMap(value: String, out: Collector[String]): Unit = {

        value
          .split(",")
          .foreach(word => {
            //将数据发送到下游
            out.collect(word)
          })
      }
    })

    flatMapDS.print()

    env.execute()
  }

}
